Spatially singlemode broad-area semiconductor laser with planar external cavity

A broad-area laser diode combined with a planar external waveguide cavity operates in the fundamental mode and reshapes the output emission into a circular 15(degree) beam. A 500 (mu)m-long by 40 (mu)m-wide laser diode with uncoated facets coupled with the uncoated ModeReShaper (MRS) planar chip has a coupling efficiency of ~40% and stabilised the fundamental mode at drive currents up to three-times threshold.